Andy Farrell admits Ireland's laboured win over Georgia was unacceptable and accused his players of lacking belief.
The Irish failed to assert their dominance over inferior opposition in Dublin as they ran out unconvincing 23-10 victors to secure second spot in Group A of the Autumn Nations Cup.
Tries from Billy Burns and Hugo Keenan helped put the hosts 20-7 in front at the break but they were unable to add to that advantage during a dismal second half, which finished 3-3.
Asked to assess the performance, head coach Farrell said: "Not good enough, not good enough.
"Certainly in that second 40, it wasn't the standard we expect of ourselves, especially playing at home.
"After a first 40 that was decent enough, flowing at times, still obviously things to fix at half-time.
"In the second half, I just thought we didn't have any courage of our own conviction.
"Georgia thoroughly deserved to earn the right to slow our game down by being total menaces at the breakdown, and all credit to them for that.
"But that's not good enough from us."
Victory for Ireland ensures they will host Scotland in next weekend's third-place play-off.
However, the manner in which it was achieved is a far more pressing matter for Farrell, who had made nine changes to the team convincingly beaten by England last weekend.
Georgia had not registered a point in the competition before arriving at the Aviva Stadium but broke their duck in fine style with a superb solo score from Giorgi Kveseladze.
While he offered a frank assessment of the overall display, Farrell also questioned the decisions of referee Mathieu Raynal to not allow first-half tries for Stuart McCloskey and James Ryan.
McCloskey's effort was chalked off after Jacob Stockdale's pass was adjudged to have travelled forward, while the French official later ignored stand-in skipper Ryan's claims he had grounded the ball.
"Two tries, one from a forward pass – I don't know the rules any more regarding that," said Farrell.
"We had a touch judge who was telling us it is a try and then a referee that says it's not.
"James Ryan is over the line just before half-time, he's got the ball down, so he says."
Fly-half Burns, making his first international start, was a bright spark on a gloomy afternoon and his 15 points helped ensure there would be no upset.
However, the England-born Ulster player was forced off with a groin issue early after the restart, severely disrupting the rhythm of the hosts.
Replacement number 10 Ross Byrne contributed the home side's only points of the second period with a penalty.
In addition to Burns, Farrell revealed he had a series of injury concerns, with hooker Rob Herring picking up a rib problem, scrum-half Conor Murray sustaining a dead leg, flanker Will Connors being forced off for a head injury assessment and winger Keith Earls suffering a back spasm.
Georgia, who are scheduled to play Fiji next weekend in the wooden-spoon match, produced arguably the moment of the match courtesy of Kveseladze's 17th-minute score.
The centre collected the ball in his own half following some slick passing, burst into Irish territory and then dummied his way past Stockdale and Burns to touch down beneath the posts.
Visiting head coach Levan Maisashvili was encouraged by his team's performance but dismissed talk of them being included in the Six Nations as premature.
"I am proud for my team. The boys scored an excellent try," he said.
"But we had a couple of opportunities and we missed them. We are a young team and we're still growing and we try to be, step by step, better and better.
"Before (being considered for) the Six Nations, we need more time to play against such a high level."
